The invention relates generally to combination can opener and knife sharpening appliances and more specifically to a combined can opener and knife sharpener which is adapted to be mounted in a depending fashion from a kitchen cabinet.
Many of the electric can openers available on the market are provided with means for sharpening knives. Typically, the electric can opener is powered by a shaded pole motor which rotates at relatively high speeds and is used to drive the feed wheel shaft of the can opener through a series of gear reductions performed by relatively inexpensive stamped or molded spur gears. It has been found that the shaded pole motors used to drive the can opener rotate at a suitable speed to power a small grinding wheel which may be mounted directly on the motor shaft and be exposed at the rear face of the can opener. Typically, a plastic guard, including guide slots for the knife blade, enclose the grinding wheel which extends beyond the rear wall of the can opener. Since the knife sharpening portion of the appliance is used relatively infrequently, it is placed on the back of the can opener housing rather than on the front where it would interfere with the use of the can opener function which takes place much more frequently.
In recent years, the limited counter space in the kitchen has become so crowded with various types of electric appliances and other food preparation utensils that there has been a movement toward mounting appliances on the wall or on the underside of cabinets so as to free more of the available counter space. As a consequence, many appliances such as coffee makers, can openers, and toaster ovens have been offered in versions which would be readily mountable on the bottom wall of a kitchen cabinet whereby the appliance would be supported at about the same height in which it would normally be used but would be spaced above the countertop.
One of the obvious problems in mounting the conventional can opener/knife sharpener appliance under the kitchen cabinet rather than providing a free standing countertop version is the fact that the knife sharpener which is conventionally on the rear wall of the can opener would be highly inaccessible or at least difficult to see and use. One possible approach to this problem might be to arrange the can opener and knife sharpener mechanism as shown in the U.S. Pat. No. 2,706,852 to Straub, et al. in which the knife sharpener is disposed in an end wall rather than a rear wall of the can opener housing. The Straub, et al. patent utilizes a series type motor which has its armature shaft extending lengthwise of the housing and driving the feed wheel shaft through a worm and worm gear. This type of gear reduction is more expensive and less efficient than the spur gear reductions which are commonly used in most can openers. In additon, the shaded pole motor with its armature shaft extending perpendicular to the front wall of the can opener housing as shown in U.S. Pat. No. 3,765,085 to Ponczek, et al. is generally favored for reasons of cost. Accordingly, it is regarded as important to provide an under-the-cabinet mounted can opener which would have the can opener mechanism on the front wall and the knife sharpening mechanism extending from the rear wall and at the same time have the appliance be easy to operate in connection with either the can opening or the knife sharpening operation.
Even though the knife sharpener attachment to a can opener is provided with guide slots to aid in positioning the knife blade properly against the grinding wheel, it is important that the attachment be in full view of the user so that the entire length of the blade may be sharpened. If the combination appliance were supported under the cabinet in such a manner that the knife sharpener was at least partly under the cabinet, thereby obscuring the user's view, it would severely limit the utility of the appliance.
There are also shown in the prior art can openers which are adapted to be mounted in several different positions so that, conceivably, a can opener might be mounted in one way to perform the can opening function and in another way to perform the knife sharpening function. Patents showing the multiple mounting features are the Straub et al. patent cited above and the Yamamoto, et al. U.S. Pat. No. 4,561,182. None of the foregoing approaches suggest a simple and effective means for mounting a combination can opener and knife sharpener having the can opener in the front and the knife sharpener in the rear.